Cocaine and amphetamine regulated transcript (CART) is a putative neurotransmitter, originally found to be upregulated by in the nucleus accumbens by psychomotor stimulants. Various studies have demonstrated CART to have psychoactive properties and to be involved in the actions of cocaine and dopamine in multiple nuclei. Therefore, understanding the anatomy and physiology of CART neurons will be important in dissecting the phenomenon of drug abuse and addiction. The overall purpose of these proposed studies is to elucidate the relationship between CART and drugs of abuse such as cocaine and amphetamine. Since multiple populations of CART neurons exist, it is important to know which of these are affected by drugs of abuse. Therefore, it will be determined if cocaine activates CART neurons in the nucleus accumbens, a nucleus long associated with drugs of abuse. Next, anatomical studies will be performed in to determine the projection patterns and terminal characteristics of this population of CART neurons in order to discover other sites at which CART may have effects. This will add to our understanding of the anatomy of drug abuse and to hypothesize treatments to alleviate this major social problem.